I have a S4 TII and my throttle body has already been ported. What I was wondering is if anybody knows of a larger throttle body to put on.

 

why do you need a larger throttle body?

 

 

The throttle body is not the restriction.
There are 400hp+ 13BT's running around with the "stock" throttle body, so I would also ask...why?


-Ted

 

Larger throttle body:







Seriously though, unless you are doing something weird, you don't need to change the throttle body...

 

Compensation?

 

Compensation no!!!

Improved throttle response

increased horsepower

increased air flow.

 

violence???

 

hey i noticed you have the apexi twin chamber bov you like it and what does it sound like?? i have one just curious.

 

All things being equal, a larger TB won't mean more HP. An engine can only flow as much as its most restrictive piece..........which isn't the throttle body.

I still say its for compensation

 

How is this possible?
Larger bores implies more volume.
More volume implies less intake velocity.
Butterfly throttles transition very aburptly, so by making them larger, you get worse throttle transients.
This is why (smaller) ITB's have such crisp throttle response...


-Ted

 

It can actually have the opposite effect if it isn't matched to the rest of the motor and it's components

 

The problem that I've run into is that my BOV starts to open at about 15 PSI of boost. It's the Greddy Type RS, and I've tried stiffer springs and tightened the adjuster down. I can get the BOV to hold shut, but it is to tight for it to release at lower boost levels ( like driving to work ). Some guys at a local speed shop said it sounds like maybe a restriction of the throttle body causing higher boost levels in the piping before the throttle body, hence causing the BOV to start opening. Yes....No....Maybe, any ideas ?

 

No.

What diameter vac line is the BOV hooked up to and where is its source coming from? Is the source dedicated to the BOV only?

 

Hmmmm... I don't know but unless he/she tune he/she an't got ****. But to each his/her own. Common sense should kick in when the amount volume is increased, the amount of air flow equal or not equal to velocity air traveling through the throttle body will dramatically change the fluxuation of air flow and terbulance. I know this already!!!

Dyno charts have already been proven in puerto rico with hp numbers clear into the 700-800 hp range.

I was just posting a pic about the different throttle bodies people are running.

Your guy's informitive point of views were well taken and noted

 

I'd think at THOSE levels, the stock TB would be a resriction

And a nice one it is BTW, is that a Syncronic BOV?

But I still think its compensating for SOMEthing............

 

what kind of BOV do you have??? How old is the BOV where is it located?...

BOV's should only open under vacuum, it may have a bad diaphram

 

everyone has an opinion be it backed up with experience or not. but hey thats what makes forum browsing so fun. all the **** talking my nizzels.

**** talking while sitting in your RX-7 thats in op right now FTW!!!!!!!!

 

Hey thanks

your to funny,

That's the racing BOV from hks

 

Perceived throttle response. A smaller movement of the pedal results in more opening of the throttle.


The reason ITBs have great response is because of less throttled volume, not because of less THROTTLE (body) volume. The response comes from the fact that there is less air to accelerate during the intake stroke and because the distance to cover is shorter. In the case of putting a larger TB on the stock intake manifold throttled volume hasn't changed that significantly (it is greater though). Its just more air is allowed in with less movement of the blade.

BC

 

I dunno... My TB seems to be flowing quite nicely...

 

Wow... That sentence is beyond words. Fluxation?!

 

The BOV is a Greddy Type RS. I have it mounted about 18" away from the TB. It's about a year old and the diaphram looks to be ok upon visual inspection. The only maybe I have would be the vacuum source is one of the ports to the rats nest under the TB and UIM. I think I might change that to one directly on the side of the manifold.

 

Yep, thats the problem (more then likely)